The Ontogeny of Spatial Ecology and Habitat Use in a Population of Cottonmouths (Agkistrodon Piscivorus) in Southwest Missouri

Juvenile snakes are usually excluded from spatial ecology and habitat use studies. However, there is evidence that ontogeny, along with sex and reproductive condition, may play a large role in spatial distribution within snake populations. I tracked eight juvenile cottonmouths (Agkistrodon piscivorus) during the summer and fall of 2008 to determine how their home ranges, rates and magnitudes of movement, and microhabitat use compared to adults previously tracked at the same site. When gravid females were excluded from the analysis, there was a strong positive effect of body size on home range size of snakes. However, the location of home ranges appears to be driven by the spatial distribution of resources, which resulted in category-specific nonrandom habitat selection. Juveniles tended to remain close to the stream and make limited movements along the stream banks within the riparian corridor of the study area. Age, sex and reproductive status all appear to strongly influence snake home range size and location, as well as habitat use. A discriminant function analysis of habitat measurements revealed that juveniles used available habitats in a more nonrandom fashion than all other groups, indicating that they are more specialized in their resource needs. Further investigation into the relationship of specific habitat cues and different age classes of snakes is warranted in order to determine how physiological needs are met at various stages of their life history